The present invention provides a process whereby a transgenic plant oil with a unique fatty acid composition, “transgenic high oleic soybean oil” or “HOSO” is used alone or as a component of industrial oils to enhance the cold pour characteristics and other performance aspects of such oils including their lubricity and biodegradability.
As is known, engine oils are used for lubrication of various metal components of internal combustion engines. The main function of these oils is to reduce wear on moving parts; it also acts to clean the engine, improve engine seals, and cool the engine by carrying heat away from moving parts. The coating of metal engine or components thereof with oil also keeps them from being exposed to oxygen, inhibiting oxidation at elevated operating temperatures acting to prevent or eliminate rust and/or corrosion. Many engine oils also have detergents and/or dispersants as components to help keep the engine clean and minimize oil retention, some of which can aid with one or more of these issues but none of which remove the problem entirely.
Typically, engine oils and lubricants have been derived from petroleum-based chemical compounds. More specifically, mineral oils, produced from petroleum, have been the primary source of engine lubricants and become the base oil for these application. Chemically, these petroleum oils are structurally composed of naphthenic, parafinic or aromatic structures. To enhance performance in one or more characteristics this base hydrocarbon stock has compounds added to it, these compounds are identified as additives. To distinguish among the characteristics, napthenic structures generally have low viscosity, good pour points and poor oxidative stability. Paraffinic structures also have common characteristics: they have higher viscosity, high pour points and good oxidative stability. Meanwhile, aromatic structures generally have very high viscosity, variable pour points and poor oxidative stability.
The bulk of a typical engine oil composition consists of hydrocarbons with between 18 and 34 carbon atoms per molecule. As mentioned above, their function is to maintain a lubricant film between moving parts. The viscosity of a liquid can be thought of as its “thickness” or a measure of its resistance to flow in these situations. To be useful in the engine oil context, the viscosity must be high enough to maintain a lubricating film at operating temperatures, but low enough that the oil can flow around the engine parts under all conditions. Often this balance is difficult to maintain. The viscosity index is a measure of how much the oil's viscosity changes as temperature changes, or its resistance to thinning relative to temperature. The higher the viscosity index of a fluid, the less it changes its composition with temperature changes. Typically lubricants contain 90% base oil (most often petroleum fractions, called mineral oils) and less than 10% additives. Additives deliver reduced friction and wear, increased viscosity, improved viscosity index, resistance to corrosion and oxidation, aging or contamination, etc. As an example, various polymeric substances are added to the base oil to improve viscosity and act as a dispersant. Micronized polytetraflouroethylene (PTFE) is added to provide lubricity and reduce engine wear. Various amines, metal phenates and zinc salts can be added as antioxidants.
Lubricants are added to gasoline in typical 2-cycle oils where a fuel source and lubrication are needed. Sulfur impurities in such fuels also provide some lubrication properties, which have to be taken in account when switching to a low-sulfur diesel; biodiesel is a popular diesel fuel additive providing additional lubricity. In 1999, an estimated 37,300,000 tons of lubricants were consumed worldwide. Automotive applications dominate this use, but other industrial, marine, rail and metal working applications are also big consumers of lubricants.
Engine oil must be able to flow adequately at the lowest temperature it is expected to experience in normal operations in order to minimize metal-to-metal contact between moving parts upon starting up the engine and/or during operation. The lowest temperature for which this pour point property is defined is the “cold pour” point and represents the lowest temperature that the fluid in question can provide the needed lubricant film to protect the identified engine, by extension; this is also the lowest temperature at which the engine can be safely operated.
It is known in the petroleum industry to source non-petroleum based oil components to assist with engine oil efficiency and viscosity issues. However, most engine oils today remain petroleum based blends composed of hydrocarbons, polyalphaolefins (“PAO”), and polyinternal olefins (“PIO”) with a relatively narrow temperature range for optimal operation. The use of lubricants and additives in engine oils for the purpose of reducing friction, corrosion and wear is well known. However, petroleum based products have significant issues that include their lack of biodegradability, high price and price variability, sourcing difficulties, sustainability and toxicity. In addition, engine oil formulas developed for a specific situation may not provide a great range of temperatures for optimal engine protection.
Given the significant limitations identified herein, lubricant manufacturers have tried for many years to use soybean oil and other vegetable oils as a base stock to meet growing demand for a more biodegradable, non-toxic, less costly and renewable product which would also have the benefit of reducing dependence on international and often distant sources of petroleum. However, until the current invention commodity vegetable oils' fatal flaws of poor oxidative stability and poor cold flow temperature properties severely limited its usefulness in the lubricant market. Likewise, the use of commodity soybean oils in grease formulations is unpredictable with extremes of heat or cold. Such soybean oil based greases can partially freeze prematurely at cold temperatures or prematurely partially melt at high temperatures.
Thus the availability of a plant-sourced renewable oil with superior cold pour characteristics and enhanced thin film strength would be a step change in engine treatment and/or maintenance. The applications for the current invention in engine maintenance, lubrication, grease formulations and engine cleaning are significant. The transgenic soybean oil of the invention, with its distinct composition, is renewable sustainable, low cost and non-toxic. It is composed of a polar vegetable oil that is attracted to metals and through this attraction offers superior film strength, a high viscosity index and is resistant to both high temperatures and pressures.
Similarly, rail curve lubrication using wayside gauge face lubrication systems is widely used by the railway industry. While the goal is to provide cost-effective solutions to reduce rail/wheel wear, energy consumption, costs and noise success in research efforts on cost-effective friction management solutions have been limited. Currently, while there are no specific performance measures available for heavy haul rail curve lubrication, the performance of in-rail lubrication seems to be poor in most cases. A substance that could improve the effective performance of rail curve grease would enhance rail curve functionality would enhance railway reliability, safety and reduce transport costs.